Grindstone wheel dresser



y 27, 1952 A. J. ENGLE 2,598,637

GRINDSTONE WHEEL DRESSER Filed May 1, 1947 INVENTOR.

Patented May 27, 1952 UNIT'E D STATES PATENT OFFICE GRINDSTO NFFEZZZZELDRESSER Andrew J. Eng'le, Chicago, 111., assignor-bf onehalf to' JamesE. Kennedy, Chicago, Ill.

Application May 1, 1947,=Serial'-No.-'745,266 2 Claims. (01. 125-11) IThis invention relates to an improved type of a grindstone or emerywheelsurface dressing device. It is particularly adapted to provide uniformlyapplied pressure to the cutting face of the grinding wheel surface.

In dressing the faceof-a worn down grindstone, an operator holds to theedge thereof a dresser tool which consists of a-s'eries of freelyrevolving toothed wheels moving about a common shaft. The shaft ismounted in a yoke or a U-type holder. The latter is generally mounted ina wooden handle to provide a" suitable and convenient means to hold thetool while it is in use. The'soderstrom' Patent Number 1,395,606 isillustrativeof one type. Another'type is shown in the Patent Number602,106 to Charles Roberts. Though there are many others'these willserve as'typical examples and will illustrate the present types'used bythe tool industry to refurbish grinding wheels.

In resurfacing grindstones'and similar devices, the operator generallypresses a hand type grindstone reconditioner suchas shown by'So'derstrom for example, against the outer periphery of the grindstone.The first impulse'of' most operators is to press quite heavily thereconditioning tool or dresser against the grindstone surface. By doingso, the grindstone is dressed-more quickly. Unfortunately the pressurenotuniformly ap plied for no matter how hard the operator triesto do soit varies as thesurface is dressed. There'- fore the application ofuniform pressureto the grindstone is haphazard. Thus in time thegrindstone tends to be out: of round and develops high and low spots.Such spotsand variations in the roundness of the grindstone aredecidedly disadvantageous for a craftsman using such deficientgrindstone cannot properly sharpenhis tools, cutting edges or even dressdown to dimensional requirements a job without encountering considerableloss of time, patience and economies of operation. 1

In addition many grindstones of natural stock or even of the so calledbetter quality having synthetic binders therein frequently have faultsand "soft spots" and shoulders within their structure. In the course ofusage such faults and soft spots are worn out more rapidly and thedepletion of the grindstone is considerably greater. The gouging orunevenness in the surface of the grindstone caused by excessive wear atsuch faults and soft spots isfurther-accentuated since a dresserwhenapplied to the face or periphery of such a grindstone tends to followthe contours of the worn out hollows and therefore the depletion of thegrindstone by gouging is increased 2' I considerably. In the -hands=ofan extremely skillful grindstone dressing mechanic, a good deal of theunevenness can beremoved with a'manuallyoperated dressing-tool. INevertheless, thegrindstone never recovers fully itsoverall efficiency,

and cannot be usefully employed -on'- projects orjobsrequiringextremelycarefuland close tolerance grinding.

It therefore is-an'objectof my invention toprovide animproved-grindstone dressing device that will apply-pressure to'thefaceof the grindstone at a uniformrate.

A further object of my invention isto provide an'improved grindstonedressing device than canbe easily, conveniently and'readily-attach'ed tothe framing of thegrindstone while d ressingtl'ie peripheral surfacethereof.

A still further object of my invention is to provide an improvedgrindstone wheel dressing device Wherein the pressure on thesurfacing'gear can be uniformly transmitted without gouging or pittingof theperipheral grinding surface of the grindstone.

A still further and'a'dditio'nal object of my invention is to provide amechanical grindstone surface dressing device wherein additionalpressure whenever required can be uniformly applied inselectedincreme'nts to the" face of the'g'rindstone.

These and other objects, adaptations, vari ations and modifications" canbe varied considerably by one'ski'lled in'the art and still be withinthe ambit of the fundamental concepts underlying my invention which isdescribed clearly and, definitively hereinbelow and of which thepreferred embodiment is illustrated in the attached d'rawing'forniin'g'a p'art'hereof.

In the drawing for sake of convenience and ease of reference, likefigures refer to similar numeral notations used in the specification.Therefore'Figure 1 shows a perspective of my improved grindstonewheeldressingdevice rest ing in position on the frame (shown principally inthe phantom sketch) of the grindstone wheel. For sake of clarity aclamping'means, such as theordinary C type clamp whichcanb'e'used tofasten the dresser to the frame is not shown.

Figure 2 is a'pla'n view, partly in section, of 7 sentially of achanneled substantially U-shape frame l whose ends I2 and I4 are open.Slidably mounted within the channel of the frame l0 and near the openends l2 and I4 thereof are bearings l6 and I8.' The bearings support theshaft 20 on which are mounted a plurality of the well known tootheddressing wheels 22 that are in contact with the grindstone periphery 24shown in a phantom sketch.

To maintain the bearings 16 and I8 in parallel alignment a yoke-likemember 26 'is provided ad frame 10. The ends 28 and 30 of the'said yokeare slidably engaged within the outstandng webs Illa and b of thechannel of the -U- shaped frame 1., A fastening means "such as screws 32fasten the ends 28 and 30 to the re spective bearings. A reenforcing bar34 transversely placed across the open end of the yoke 26 addsrigidity'and strength and prevents wobble of the toothed gear likedressers'22 when pressure is applied during the dressing process. 4 Atthe upper part or apex of the yoke 26 is a hole 36.; On each side of thehole 36 in the yoke are placed washers 38. Through the yoke hole 36 andwashers 38 is inserted a spindle 40. The principal part of the uppermostportion thereof isa thread 42 which is engaged by a nut 44. The nut 44is fixed immovably to the frame of the channel In. The top'of thespindle 40 termiopen.

In this manner grindstones badly pitted can be dressed smoothly forthere is at all times a uniform pressure applied across the face of thestone.

In hand operation, the operator cannotmaintain a uniform pressure acrossthe face of the stone for the pit in the stone may come up unexpectedlor even at times there may be a hole in the stone which the dressingdevice may un- I handoperated'grindstone dressing device strike thru andcause'marring as well as damage;

' As the stone is dressed down, more pressure is 1 imparted byturningthe knob 46 and which is within the open areaof the U-shapedchannelcover. Whenrthis occurs, then the teeth of a transmitted fromlthescrew 42 thru. collar 4! on the washer 39'and in turn onthe yoke 26. IThe latter transmits the pressure to the bearings l6 and i8 slidablymounted within the channel frame- 10. As the bearings l6 and I8 moveforward inparallel juxtaposition; they carry the shaft likewise' andthus in turn transmit the pressure to the cutting teeth 22. 1 Thepressure is applied uniformly to the face 5 of the grindstone for thebearings move simul-..

taneously in rigid parallel relationship; If for some reason,the teethshall encounter a pitor I a depression on the face of the stone, thenthe nates in a handwheel 46 which propels or re- V l Small bar 54 or ifdesired a bar slightly .longer springi48 prevents the teeth from fallinginto or following such depression. As the surface is' dressed down,the'teeth will eventually turnout a uniformly circular stonelwhose facewill be dressed parallel to .the' edges of the teeth 22.

Having described. hereinabove the essential concepts underlying myinventionfI wish to include all those variations and modificationsincluding the preferred embodiment as illustrated in the attachedvdrawing that will fall within the I scope of the spirit of my inventionas definedin than the width of the channel frame [0 can be p welded tothe bottom and, near the'ends l2 and 14 of the frame In. These bars54act'as stops when the dresser is used, or at'times, they prowide aconvenient place to hold the dresser to the frame of the grindstone bymeans of some fastening device such as an ordinary c-type clamp(not-shown). r I

In actual use the bars 54 mounted on the lowermost part of thechannel'frame 10 are butted against or evenplaced'on the edge of theframe 56 of thegrindstone. 24. It maybe.

held against the frame by the operator orheld jinpositionby any holdingmeans such asthe conventional =C-type clamp. In placing thedressingdevice in position for action it is necessary that the dressingteeth edges be placed in the hereunto-appended claims. I Iclaim:

1. A 'grindstone dressing; device comprising a U-shaped channel? thesaidu -shaped'channel formed into a U-shapedframe, "an openin betweenthe extending armsjof said u-sh'apecl frame, the said U-shaped framearms having open ends thereon, bearing members slidably mountedwithin'the u -shaped channels forming T the said open end arms," a meansto hold said the desired position so that they contact uni- I L formlythe face 24 of the stone to be dressed.

When the device is fastened properly in place ;and with the grindstonerevolving, the operator igradually turns the hand wheel 46 until thegear teeth .22 just barely touch the 'grindstone face 24.

hand wheel 46 and the movement of the yoke 26, 'since it acts on thewasher 38 and in turn Qon the yoke 26, both of which are slidablymounted on the .spindle 46. The operator then I turns again slightly thehand wheel 46 and the V ;teeth 22 are'gradually but uniformly pushedjacross gface. If the face 24 Jof the stone should be ipitted orgougedthen the spring-48 by acting on the yoke 26v thru'the washer 38 keepsthe teeth from striking into the pit and thus breaking it The spring 48cushions the action of the the entire face 24 .of the grindstonesurbearing members in parallel juxtaposition within the said open'endarms, the said meansto hold said bearing members in parallel relationcomprising a V-shaped yoke, the ends of said '-"-yoke attached to saidslidablebearing members,

the apexof said oke having therein an opening, a spindle insertedtherethrough, screw threads on that part of the said spindle above thesaid opening in thelapex of said yoke, a

Z threaded nut mounted within the base of saidf U-shaped frame to engagethesaid threads on the spindle, a hand wheel mounted fixedly on that endof the said spindle. protruding through said U-shaped frame base, and asprin mount- 'ed on that part of said spindle protruding through saidapex of theyoke to'keep the apex of said yoke incontacting.juxtaposition with the said threaded portionof said spindle.5

2. In the apparatusof claim 1, a helical spring j mounted 'on the; lowerportion of said spindle protruding within the saiclyoke, to maintain.

the said apexin:contacting. juxtaposition with the threacled portion ofthesaid spindle.

-ANDREW'J. ENGLE'."

7 (References on following" page) 5 REFERENCES CITED Number Thefollowing references are of record in the 981,310 file of this patent:UNITED STATES PATENTS 5 Number Name Date Re. 15,865 Misner June 24, 1924Number 268,541 Roystone Dec. 5, 1882 9 ,63 548,272 Robischung Oct. 22,1895 1 2, 49 760,926 Schroeder May 24, 1904 10 7 ,5 980,654 Mason Jan.3, 1911 7 Name Date Sterling Jan. 1 1911 Roberts Apr. 5, 1921 Hohnhorstet a1. June 4, 1929 FOREIGN PATENTS Country Date Austria Jan. 10, 1923Switzerland Dec. 1, 1923 Great Britain Feb. 23. 1922

